textproduct: Quad Cities

KEY MESSAGES

- Near record/record high temperatures today, and are possible again on Tuesday mainly south of I-80. - Severe weather potential late Tuesday afternoon through evening with all hazards in play. The greatest threat area is mainly near/southeast of a line from Sterling to the Quad Cities to Mount Pleasant where an Enhanced Risk (level 3 of 5) is in place. Localized flooding is possible with any repeated rounds of storms.

- Active pattern for the latter half of the week into the weekend with additional precipitation chances, some of which could be snow as temperatures turn cooler and more seasonable.

SHORT TERM /THROUGH TONIGHT/

Issued at 333 AM CDT Mon Mar 9 2026

Anytime you start your day off with temperatures near normal highs you know you're headed for an anomalously warm day. Low level warm advection will continue to strengthen for much of the day ahead of an approaching cold front. Progged 850 hPa temperatures of 12c to 15c are greater than 99th percentile of climatology per NAEFS and at or above the max for DVN for the date per SPC sounding climatology. This anomalously warm airmass combined with abundant sunshine and a favorable southwest low level flow will lead to record breaking highs in the 70s for areas south of Hwy 30. The cold front, which currently is just north/west of the Twin Cities early this morning, aided by a 5-7 mb post frontal pressure rise is slated to make inroads this afternoon north of Hwy 30. This will result in highs there in the 60s, albeit still well above normal and even potentially still near record territory as evidence by the 65 record high at Dubuque - see the Climate section below.

The cold front is expected to continue sagging south into the area tonight, but with weakening post frontal pressure rises and alignment more parallel to the mid level flow it is expected to slow and eventually stall out most likely south of Hwy 30 to I-80. This will lead to quite a low temperature contrast across the area with lower 40s and possibly a few upper 30s near Hwy 20 aided by veering flow to the northeast with a chilly Lake Michigan influence (water temps upper 30s and 40s). Meanwhile, south of the front an unseasonably mild night is in store with lows in the 50s. The most challenging low temperature forecast and subsequent higher error bar (greatest uncertainty) will be along the Hwy 30 through I-80 corridors. Can't rule out some fog development near to just south of the boundary, but lower confidence as we potentially develop some stratus with the nocturnal LLJ and also could bring in some high clouds ahead of our next system.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 333 AM CDT Mon Mar 9 2026

Tuesday remains a day to be vigilant for severe weather, particularly from QC metro and especially points south/east where SPC continues the Enhanced Risk or level 3 of 5 risk. All hazards are possible, though greatest concerns are for supercells yielding a significant hail threat (golfball size or larger) and a few tornadoes in/near the quadrant mainly S/E of the Quad Cities into northeast MO and central IL. This zone has the overlap of the best instability and an impressive kinematic environment in the pre-frontal warm sector ahead of a surface low translating eastward along the frontal zone. This setup like most has some uncertainty. This includes the potential for a weaker and somewhat nebulous surface low, which is likely tied to the continued slight slowing of the main synoptic scale ascent attendant to the phasing of a Rockies shortwave and an ejecting low from the Baja of California. Large scale height falls (100-150+ m at 500 hPa) don't overspread the area until late Tuesday night into Wednesday, thereby casting some uncertainty with timing/arrival of forcing, strength of the surface low and amount of backed low level flow. Soundings also show the presence of an EML, which in the absence of ascent will likely suppress convection for much if not all of the daytime hours on Tuesday. That being said, it would seem as though an increasing 40+ kt nocturnal LLJ should support some development probably closer to 00z in/near our south/east service area into the evening. With the presence of the earlier EML and given the impressive kinematics we will likely see discrete supercells if storms do indeed fire. The 03z RAP and 00z NAM/HRRR models also show a 50+ kt jet max shown to overspread SE Iowa and WC Illinois around 00z through 03z. The current SW to NE orientation would place the favored right entrance region or favorable lift quadrant largely just south/east of our service area or very nearby for a close shave. Something else of note is the Bunkers right Supercell motion is roughly 250-260 degrees at 25-35+ kt. Thus, with that motion there will be the potential for discrete surface based supercells with a tornado threat to cross the front and become elevated reducing the threat to large hail. Where this occurs will be pending the location of the front, but consensus seem to favor between I-80 to Hwy 34... thus south of Hwy 34 would stand the best potential for sustained tornado producing supercells or even further south/east as it looks right now. Bottom line, the potential is there for significant severe weather Tuesday late afternoon through evening, so you'll want to pay close attention to the weather especially for areas from the Quad Cities south/east into central IL and northeast MO.

This severe threat will likely diminish mid to late evening, but the arrival of the deeper synoptic scale lift and residual boundary will support additional rounds of showers and storms, particularly south of Hwy 30 and especially near/south of I-80. With PWATs of 1.1 to 1.3 inches or roughly 2+ sigma there is the potential for localized flooding with any repeated rounds of convection and heavy downpours. 00z HREF LPMM through 00z Wednesday shows pockets of 1-2 inches and ensemble means continue to hint also at a swath(s) of similar amounts 1-3 inches. WPC ERO continues to highlight south of I-80 with a Slight Risk for excessive rainfall. Due to the ongoing drought much of the area will see beneficial rainfall, but any areas again that get into repeated activity given the anomalous moisture could wind up with several inches in a short time that could result in a flooding threat. High pressure will build in behind this system for later Wednesday and Wednesday night ushering in drier and cooler conditions. The break from the active weather will be short-lived however, as deterministic models and ensembles support a clipper system diving through Upper Midwest and Great Lakes Thursday. Consensus takes the track of the low to our north, but strengthening warm advection/isentropic ascent will bring a good chance for a quick shot of mainly rain Thursday night - highest probabilities (60-70%) north of Hwy 30. Can't rule out a few flakes north of Hwy 20, but the strength of the WAA should keep this mostly if not all rain.

Heading into the weekend we remain in active W/NW flow aloft and will see periodic precipitation chances, as waves/clipper systems are shuttled down in/near the region. We will likely continue to see a roller coaster of temperatures - quick warming in the warm advection followed by cooling in the wake of these systems. Despite still some fairly large IQRs in NBM during this time they are centered near seasonal normals.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 532 AM CDT Mon Mar 9 2026

VFR conditions will persist through 06z/10th. After 06z there is a chance (20-30%) for patchy fog and stratus and lower conditions of IFR/MVFR. LLWS will be the main concern until 14z this morning, as W/SW winds aloft near 2kft agl of 40-50 kt outpace the surface winds around 10 kt with occasional gusts near 20 kt. After 14z, with mixing southerly surface winds should gust with more frequency to around 20 kt. The winds will become light this afternoon and evening, and variable at KCID/KDBQ while remaining predominantly from the south at KMLI/KBRL, as a frontal boundary sags into the region. Weak convergence could bring some fog and stratus potential near the boundary overnight, but low confidence on location/extent combined with it being late in the TAF period precludes mention at this time. In addition, a strengthening NE flow off Lake Michigan could advect in some lower stratus at KDBQ and possibly KMLI late in the period, but again confidence is too low to add mention at this range.

CLIMATE

Issued at 333 AM CDT Mon Mar 9 2026

Record High Temperatures:

March 9: KBRL: 74 in 1986 KCID: 68 in 2021 KDBQ: 65 in 1977 KMLI: 71 in 2021

March 10: KBRL: 76 in 1955 KMLI: 74 in 1955

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.